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ICKS AND MITES form the order Acari, a huge, diverse group of about 300 families and 30,000 species.

They arc found in every habitat, including aquatic ones, and have a wide range of lifestyles. Many are significant pests of crops and stored produce or parasitize humans and other animals.

Most species are less than Vsiin (1mm) long, although ticks can be much larger, especially following a blood meal. The body has no distinctive divisions, and the short abdomen has no segments. The mouthparts are carried on a special extension. The chelicerae are two- or three-segmented pincers or are adapted for piercing and sucking. Both the adults and nymphs have four pairs of six-segmented walking legs, although the first-stage larvae have only three pairs.

0rdcr ACARI

Family AOARII)AK

Acarids

Also called storage mites, most acarids are pale in coloration. The abdomen has long hairs. The legs of these mites can be long but in some species are extremely short.

• i jit CYCLE Eggs are laid wherever the mites feed. As with most mites, there arc three nymphal stages. Many live in association with certain arthropods, and some are found in rotting matter.

• OCCl RRENCE Worldwide. In fresh or dried stored products, cheese, fungi, beehives, organic detritus, and inside mattresses.

• REMARK A few acarids arc pests of dried, stored food. Some cat mammalian skin or bite humans and can cause skin conditions such as dermatitis or trigger allergies such as asthma.

long body hair.

long body hair.

AcARl'S s/R(), the Hour Mite, is found all over the world in flour, grain, and various seeds in stores and mills. If conditions are suitable, huge populations can build up.

Length Under'/win (1mm)

0rder acari

Family ARC» AS I DAE

Soft ticks

These ticks usually have a rounded, berry like body, although some are flat dorsoventrally. The tough, leathery body can be either wrinkled or folded, and the chelicerae arc adapted for cutting through the skin of their hosts - mammals (including bats), birds, and snakes. They are ectoparasitic and feed mostly at night.

• LIFE Cycle Eggs are typically laid in the nests and burrows of their hosts, and both adults and nymphs live mainly in association with these animals.

• OCCl JRRENCE Worldwide, especially in warm, dry regions. Typically in hosts' nests and burrows.

• REMARK Many soft ticks are carriers of disease and are pests of various domestic animals, especially poultry.

► pedipaips leathery body leathery body pale, legs pale, legs rurved

Arc as ri'rsicus is a pest of domestic chickens and other poultry in many parts of the world. It transmits a disease called fowl relapsing fever.

translucent body t turns red after a blood meal pedipalps <

Jour pairs of similarly s ized legs

0rder ACARI

Family DkrmaNYSSIDAK

No. of species 25

translucent body t turns red after a blood meal pedipalps <

dermanyssids

I hese mites use their needlelike chelicerae to feed on the blood of birds and mammals. After a blood meal, their color changes from pale gray to red. Many females have a single dorsal plate with short hairs.

• LIFE CYCLE Males use their chelicerae to transfer sperm to the female. Kggs are laid in places such as nests, burrows, and poultry houses. The first-stage larva does not feed, although subsequent nymphal stages do.

• OCCURRENCE Worldwide. In association with bird and mammal hosts.

• REMARK Certain species arc significant pests of poultry, and some carry diseases that can kill animals and also affect humans.

Jour pairs of similarly s ized legs l)ERMANYSSl S GAI.UNAE, the Red Poultry Mite, is found all over the world on a wide range of birds. These mites feed at night and hide in crevices during the day.

Feeding habits

0rder ACARI

Family JxodidaK

No. of species ^q

Hakd ticks

1 hese flat ticks have a very tough, sometimes patterned plate on their back. In males, it covers the whole body; in females and immature ticks, it covers only the front half. The soft, flexible abdomen allows large blood meals to be taken from the animal hosts on which these ticks are found. Coloring varies from yellow to red- or black-brown, and some species arc highly marked.

• life Cycle After mating, a female gorges herself on blood and then drops off the host to lay a batch of eggs among vegetation. Six-legged larvae emerge, crawl up grass blades, and attach themselves to a passing host. A larva feeds for a few days and then drops off the host to molt into an eight-legged nymph. The nymph attaches itself to a host and feeds for several days before once again dropping off to molt into an adult.

• OCCtJRRENCE Worldwide. In association with bird, mammal, and some reptile hosts.

• REMARK Many hard ticks transmit disease and are serious pests of domestic animals such as cattle, sheep, horses, and poultry. Some also carry viral diseases that affect humans, including encephalitis, Lyme disease, tick typhus, and Rocky Mountain Spotted Fever.

AMMYOMMA AMERICANVM, the Lone Star l ick, attacks a range of mammals and will also bite humans. It is found in the central states of the I IS.

palp in females, dorsal plate covers only front half of body mouthparts front part of head (" false head") projects forwards

four similar pairs of legs pale patch on rear of dorsal plate punctured surface palp in females, dorsal plate covers only front half of body four similar pairs of legs pale patch on rear of dorsal plate punctured surface mouthparts front part of head (" false head") projects forwards

0rder Acari fami|y Laklapidae

No. of species ^q

0 0

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